1. Technical Field
The present invention relates to a projector which projects image light.
2. Related Art
A projector is an optical device which forms image light by modulating lights emitted from a light source according to image information, and projects the image light on a screen or the like. The projector is used for various purposes such as a presentation held in a corporation and lessons given in a classroom. There is a demand for a projector capable of providing images having high luminance so as to increase visibility in a wide meeting room or classroom. Thus, a projector including a plurality of discharge type light sources (lamps) such as extra-high pressure mercury lamps has been proposed (for example, see JP-A-2004-62137). According to the discharge type light source, the electrode position in the arc tube provided on the light source is appropriately controlled during the manufacture process in such a manner as to emit lights with high efficiency.
Though not specifically described, it is considered that the plurality of light source devices (light sources) according to the technology disclosed in JP-A-2004-62137 are contained in positions opposite to one another in the up-down direction. It is also considered that some light sources of the light source devices are disposed in positions opposite to the position adjusted by the manufacture process in the up-down direction. When the light source is oppositely positioned, arc generated between the electrodes in the arc tube is shifted from the position adjusted by the manufacture process in some cases due to the gravity, convection of filler gas or the like. When the arc position is shifted, discharge is not efficiently achieved. In this case, decrease in luminance may be caused.